webapp in container testing stategy

Hello;
I have a web app that calls webservices and servlets to actually funtion.
I have been asked to come up with a way to validate behavior in the actual container. Not using mocks and stubs and preferably not use the webapp presentation to test the server side function calls.

Hoping for some guidance on current strategies. What I am finding.
one of the desired goals is to not a

(the old way): HTTPUNIT/HTMLUNIT/Cactus ontop of junit - effective, developers have experience using it. Looks like it can be a real pain if you have to build long complex web conversations.